<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        const obj = {}
        console.log(obj)
        function Test(fn){
            this.say = fn
        }
        Test.prototype.say = ()=>{
            console.log('say')
        }
        console.log(Test.prototype,'test')
        console.log(Function.prototype.__proto__,'proto')
        const test = new Test(function(){
            console.log('my say')
        })
        console.log(test,'test1')
        console.log(test.__proto__ === Test.prototype)
        test.say()
    </script>
</body>
</html>